Grand Prismatic Spring United States of America

The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the US, and it is the 3rd largest in the world. Don't let its calm blue colored water fool you. The center of Grand Prismatic Spring is so hot that not even the hardiest of bacteria can survive it's temperature. The vivid colors in the spring are the result of pigmented bacteria in the microbial mats that grow around the edges of the water.